<!DOCTYPE html>
<html lang="en">
    <head>
        <meta charset="utf-8">

        <style type="text/css">


			div{
				 width: 300px;
				 height: 300px;
				 border: 1px solid green;
				 overflow: scroll;   /* 添加滚动条 */
                 /* hidden     将超出部分进行隐藏 */
                 /* auto	
  如果内容超出盒子，那么给盒子设置滚动条，如果内容没有超出盒子，那么不显示滚动条。 */




			}
        </style>
    </head>
    <body>

    	 <div>
    	 	<p>asdfasdfasdf</p>
    	 	<p>asdfasdfasdf</p>
    	 	<p>asdfasdfasdf</p>
             <p>asdfasdfasdf</p>
             <p>asdfasdfasdf</p>
    	 	<p>asdfasdfasdf</p>
    	 	<p>asdfasdfasdf</p>
             <p>asdfasdfasdf</p>
             <p>asdfasdfasdf</p>
    	 	<p>asdfasdfasdf</p>
    	 	<p>asdfasdfasdf</p>
    	 	<p>asdfasdfasdf</p>
    	 
    	 </div>
    </body>
</html>